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author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2019-05-14 15:43:05 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-05-14 19:52:49 -0700 |
commit | 2c64e9cb0b6b858901e9a386860d7d929d1cbaeb (patch) | |
tree | 749da0ef8f5d478680a523c877fb0e16fc18409c /lib/div64.c | |
parent | b5c56e0cdd62979dd538e5363b06be5bdf735a09 (diff) | |
download | linux-2c64e9cb0b6b858901e9a386860d7d929d1cbaeb.tar.gz linux-2c64e9cb0b6b858901e9a386860d7d929d1cbaeb.tar.bz2 linux-2c64e9cb0b6b858901e9a386860d7d929d1cbaeb.zip |
lib: Move mathematic helpers to separate folder
For better maintenance and expansion move the mathematic helpers to the
separate folder.
No functional change intended.
Note, the int_sqrt() is not used as a part of lib, so, moved to regular
obj.
Link: http://lkml.kernel.org/r/20190323172531.80025-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Ray Jui <rjui@broadcom.com>
[mchehab+samsung@kernel.org: fix broken doc references for div64.c and gcd.c]
Link: http://lkml.kernel.org/r/734f49bae5d4052b3c25691dfefad59bea2e5843.1555580999.git.mchehab+samsung@kernel.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/div64.c')
-rw-r--r-- | lib/div64.c | 192 |
1 files changed, 0 insertions, 192 deletions
diff --git a/lib/div64.c b/lib/div64.c deleted file mode 100644 index ee146bb4c558..000000000000 --- a/lib/div64.c +++ /dev/null @@ -1,192 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com> - * - * Based on former do_div() implementation from asm-parisc/div64.h: - * Copyright (C) 1999 Hewlett-Packard Co - * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com> - * - * - * Generic C version of 64bit/32bit division and modulo, with - * 64bit result and 32bit remainder. - * - * The fast case for (n>>32 == 0) is handled inline by do_div(). - * - * Code generated for this function might be very inefficient - * for some CPUs. __div64_32() can be overridden by linking arch-specific - * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S - * or by defining a preprocessor macro in arch/include/asm/div64.h. - */ - -#include <linux/export.h> -#include <linux/kernel.h> -#include <linux/math64.h> - -/* Not needed on 64bit architectures */ -#if BITS_PER_LONG == 32 - -#ifndef __div64_32 -uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base) -{ - uint64_t rem = *n; - uint64_t b = base; - uint64_t res, d = 1; - uint32_t high = rem >> 32; - - /* Reduce the thing a bit first */ - res = 0; - if (high >= base) { - high /= base; - res = (uint64_t) high << 32; - rem -= (uint64_t) (high*base) << 32; - } - - while ((int64_t)b > 0 && b < rem) { - b = b+b; - d = d+d; - } - - do { - if (rem >= b) { - rem -= b; - res += d; - } - b >>= 1; - d >>= 1; - } while (d); - - *n = res; - return rem; -} -EXPORT_SYMBOL(__div64_32); -#endif - -/** - * div_s64_rem - signed 64bit divide with 64bit divisor and remainder - * @dividend: 64bit dividend - * @divisor: 64bit divisor - * @remainder: 64bit remainder - */ -#ifndef div_s64_rem -s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder) -{ - u64 quotient; - - if (dividend < 0) { - quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder); - *remainder = -*remainder; - if (divisor > 0) - quotient = -quotient; - } else { - quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder); - if (divisor < 0) - quotient = -quotient; - } - return quotient; -} -EXPORT_SYMBOL(div_s64_rem); -#endif - -/** - * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder - * @dividend: 64bit dividend - * @divisor: 64bit divisor - * @remainder: 64bit remainder - * - * This implementation is a comparable to algorithm used by div64_u64. - * But this operation, which includes math for calculating the remainder, - * is kept distinct to avoid slowing down the div64_u64 operation on 32bit - * systems. - */ -#ifndef div64_u64_rem -u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder) -{ - u32 high = divisor >> 32; - u64 quot; - - if (high == 0) { - u32 rem32; - quot = div_u64_rem(dividend, divisor, &rem32); - *remainder = rem32; - } else { - int n = fls(high); - quot = div_u64(dividend >> n, divisor >> n); - - if (quot != 0) - quot--; - - *remainder = dividend - quot * divisor; - if (*remainder >= divisor) { - quot++; - *remainder -= divisor; - } - } - - return quot; -} -EXPORT_SYMBOL(div64_u64_rem); -#endif - -/** - * div64_u64 - unsigned 64bit divide with 64bit divisor - * @dividend: 64bit dividend - * @divisor: 64bit divisor - * - * This implementation is a modified version of the algorithm proposed - * by the book 'Hacker's Delight'. The original source and full proof - * can be found here and is available for use without restriction. - * - * 'http://www.hackersdelight.org/hdcodetxt/divDouble.c.txt' - */ -#ifndef div64_u64 -u64 div64_u64(u64 dividend, u64 divisor) -{ - u32 high = divisor >> 32; - u64 quot; - - if (high == 0) { - quot = div_u64(dividend, divisor); - } else { - int n = fls(high); - quot = div_u64(dividend >> n, divisor >> n); - - if (quot != 0) - quot--; - if ((dividend - quot * divisor) >= divisor) - quot++; - } - - return quot; -} -EXPORT_SYMBOL(div64_u64); -#endif - -/** - * div64_s64 - signed 64bit divide with 64bit divisor - * @dividend: 64bit dividend - * @divisor: 64bit divisor - */ -#ifndef div64_s64 -s64 div64_s64(s64 dividend, s64 divisor) -{ - s64 quot, t; - - quot = div64_u64(abs(dividend), abs(divisor)); - t = (dividend ^ divisor) >> 63; - - return (quot ^ t) - t; -} -EXPORT_SYMBOL(div64_s64); -#endif - -#endif /* BITS_PER_LONG == 32 */ - -/* - * Iterative div/mod for use when dividend is not expected to be much - * bigger than divisor. - */ -u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder) -{ - return __iter_div_u64_rem(dividend, divisor, remainder); -} -EXPORT_SYMBOL(iter_div_u64_rem); |